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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:2
UID:UW-Physics-Event-5308
DTSTART:20200207T193000Z
DURATION:PT1H0M0S
DTSTAMP:20260309T062556Z
LAST-MODIFIED:20200210T163257Z
LOCATION:5280 Chamberlin
SUMMARY:Einstein’s Microscope: Uncovering Small-Scale Dark Matter St
 ructures with Novel Gravitational Lensing Probes\, Theory Seminar (Hig
 h Energy/Cosmology)\, Liang Dai\, Institute for Advanced Study
DESCRIPTION:The physical nature of the astrophysical dark matter (DM) 
 is a fundamental question in cosmology. The clustering structure of DM
  on sub-galactic scales is key to distinguishing between various viabl
 e DM models which all make successful predictions about the large-scal
 e structure and galaxy formation\, but empirical tests have been funda
 mentally hindered by the lack of electromagnetic tracers of sub-galact
 ic structures. In this talk\, I aim to introduce novel and practical g
 ravitational-lensing based methods which can be employed to push forwa
 rd this research frontier. I will first discuss the new phenomenon of 
 extremely magnified cosmological sources as deep imaging of strong len
 sing clusters has recently started to uncover\, and explain how this p
 henomenon can be exploited as a sensitive probe of compact halo object
 s\, non-luminous DM subhalos smaller than those who host dwarf galaxie
 s\, and even (sub-)planetary mass DM minihalos as expected in the axio
 n DM scenario. The full scientific potential of these new ideas will b
 e realized as forthcoming photometric surveys will greatly expand the 
 catalog of highly magnified lensed galaxies and deep follow-up observa
 tions with space-borne or ground-based optical/infrared telescopes wil
 l enable detailed studies of their lensed appearances. I will also dis
 cuss the exciting prospect to exploit lensing of alternative extragala
 ctic sources such as fast radio bursts and gravitational waves from me
 rging black holes to probe small-scale DM lenses. In particular\, I wi
 ll explain how one can extract unique information by observing wave di
 ffraction of gravitational waves\, which would be typically infeasible
  with electromagnetic sources.
URL:https://www.physics.wisc.edu/events/?id=5308
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